_Associated habitual movements in the lower animals_.--
I have already given in the case of Man several instances
of movements associated with various states of the mind or body,
which are now purposeless, but which were originally of use,
and are still of use under certain circumstances. As this subject
is very important for us, I will here give a considerable number
of analogous facts, with reference to animals; although many
of them are of a very trifling nature. My object is to show that
certain movements were originally performed for a definite end,
and that, under nearly the same circumstances, they are still
pertinaciously performed through habit when not of the least use.
That the tendency in most of the following cases is inherited,
we may infer from such actions being performed in the same manner
by all the individuals, young and old, of he same species.
We shall also see that they are excited by the most diversified,
often circuitous, and sometimes mistaken associations.

Dogs, when they wish to go to sleep on a carpet or other hard surface,
generally turn round and round and scratch the ground with their
fore-paws in a senseless manner, as if they intended to trample down
the grass and scoop out a hollow, as no doubt their wild parents did,
when they lived on open grassy plains or in the woods. Jackals, fennecs,
and other allied animals in the Zoological Gardens, treat their straw
in this manner; but it is a rather odd circumstance that the keepers,
after observing for some months, have never seen the wolves thus behave.
A semi-idiotic dog--and an animal in this condition would be particularly
liable to follow a senseless habit--was observed by a friend to turn
completely round on a carpet thirteen times before going to sleep.

Many carnivorous animals, as they crawl towards their prey and prepare to rush
or spring on it, lower their heads and crouch, partly, as it would appear,
to hide themselves, and partly to get ready for their rush; and this habit
in an exaggerated form has become hereditary in our pointers and setters.
Now I have noticed scores of times that when two strange dogs meet on
an open road, the one which first sees the other, though at the distance
of one or two hundred yards, after the first glance always lowers its bead,
generally crouches a little, or even lies down; that is, he takes the proper
attitude for concealing himself and {illust. caption = for making a rush
or FIG. 4.--Small dog watching a cat on a spring, although the road table.
From a photograph taken is quite open and The distance Mr. Rejlander.} great.
Again, dogs of all kinds when intently watching and slowly approaching
their prey, frequently keep one of their fore-legs doubled up for a long time,
ready for the next cautious step; and this is eminently characteristic
of the pointer. But from habit they behave in exactly the same manner
whenever their attention is aroused (fig. 4). I have seen a dog at the foot
of a high wall, listening attentively to a sound on the opposite side,
with one leg doubled up; and in this case there could have been no intention
of making a cautious approach.

Dogs after voiding their excrement often make with all four
feet a few scratches backwards, even on a bare stone pavement,
as if for the purpose of covering up their excrement
with earth, in nearly the same manner as do cats.
Wolves and jackals behave in the Zoological Gardens in exactly
the same manner, yet, as I am assured by the keepers,
neither wolves, jackals, nor foxes, when they have the means
of doing so, ever cover up their excrement, any more than do dogs.
All these animals, however, bury superfluous food. Hence, if we
rightly understand the meaning of the above cat-like habit,
of which there can be little doubt, we have a purposeless remnant
of an habitual movement, which was originally followed by some
remote progenitor of the dog-genus for a definite purpose,
and which has been retained for a prodigious length of time.

Dogs and jackals[15] take much pleasure in rolling and
rubbing their necks and backs on carrion.